Monoazo dye and process of making same.



- alpha-naphthol are disso UNITE srarrns TEILO KROEBER, OF BASEL, SWITZE LAN 'EtLAlElD, ASSlGEl-Oli TO THE FIRM OF SOCIETY OF CHEMICAL llflDUSTRY ll'l BilrSLlE-I, OF BASEL, SWITZER- Specification of Letter-c Patent. I

racemes Nov. 13, 19cc.

Application filed January 30,1906. Serial No. 298,72, (Specimena) To all whom it may concern:

Be it known thatl, TniLo Knonnnn, chemist and doctor of philosophy, a subject of the Duke of SaXc-Altenburg, and a resident of Basel, Switzerland, have invented new and useful Improvementsin Monoazo Dyes and Process of Making the Same, of which the following is a clear and complete specification.

It is known that the orthodiazonaphthoh sulfonic acidsas, for instance, the 1 :2-diazonaphtholrsulfonic acid-are not able to be combined smoothly with alpha-naphthol in alkaline solutions-that is to say, in solutions containing a caustic alkali or an alkaline carbonate, as it is usually practiced in the manufacture of azo dyestufis. 1 have made the surprising discovery that nevertheless a smooth. combination of an orthodiazonaphtholsulfonic acid with alpha-naphthol takes place when it is eflected in presence of suitable neutral or basic organic compoundsas, for instance, alcohol, pyridin, anilin, &c. -and that the presence of these organic compounds facilitates generally the combination of the orthodiazonaphtholsulfonic acids with azo coloring-matter components.

The new monoazo dyestufis derived from orthodiazcnaphtholsulfonic acids and alphanaphthols dye wool in an acid-bath brownishviolet tints, which turn to beautiful black fast to milling, washing, potting, and light when subsequently treated with chromium compounds. They dissolve in water with violet to blue colorations and in concentrated sulfuric acid with greenish-blue colorations. Example: Forty-five parts, by weight, of ved in four hundred parts, by Wei ht, of alcohol (of ninety-five per cent.') wit the addition of eighty parts, b weight, of soda-lye, (of thirty per cent.) 'hile stirring and at a low temperature of about 5 to 10 centigrade such a uantity of,

dry and pulverized diazonapht olsulfonic acid as corresponds to seventy-two parts, by 'weight, of 1 :2 :4-amidonaphtholsulfomc acid,

(of one hundred per cent.) are gradually added. The reaction mass shows at first a rddishwiolet color,'which turns gradually to greenish blue, the separation of the dyestuff partly taking place at the same time. After'about one hour it is heated, at about 45 centigrade, until-the complete disappearresorcin solution in the usual Well-known maimer. The combination being comleted, the thus obtained paste is dissolved in fifteen hundred parts, by'weight, of hot water, (of to centigrade.) On the addition of a certain quantity of hydrochloric acid (of 19 Baum) as, for example, of about sixty parts, by weightthe dyestufl' separates as a crystalline brown mass which is separated b filtration, pressed, and dried.

It forms a roWnish-black powder with bronze-like luster soluble in hot water with a violet color, in concentrated sulfuric acid with a greenish-blue color, blackish-violet flakes being separated on the addition of icewater to the said solution.

The dyestufi produces on wool in an acidbath' brownish-violet shades, which on treatment with a chromium compound change to a beautiful bluish black of great iastness against milling, washing, and li ht. The shades are not altered by artificial light.

The described process for the perature, quantity, and force of the employed alcohol.,.,-Aliso other suitable organic diluentsa's, for instance, pyridin, anilin, &c. may be substituted for the alcohol.

in the foregoing example the 1:2-diazohaphtholsulfonic acid may be replaced by other orthodia'zonaphtholsulfonic acids-as,' for instance, 1:2-diazonaphthol-6-sulfonic acid, 2:l-diazonaphthol-4-sulfonic acid, 2:1- diazonaphthol-5 sulfonic acid, 1 :2 diazonaphthol-3 :G-disulfonic acid, 1:2-diazonaphtholizB-disulfonic acid, 2:1-diazonaphtholing of the diazo compound, which may be tested on test paper with a warm alkaline roduction of the said dyestufi may be varie as to tem- 5:7disulfonic acid, &c.-whereby similar monoa'zo dyestuffs are obtained, which dis solve in dilute solutions of sodium carbonate with blue color and in concentrated sulfuric acid with greenish-blue color.

VVhatIclaim is' v 1; 'llbe rocess for the manufacture ofmonoazo yestuiis which, consists in -com bining an orthodiazonaphtholsulfonic acid with'an azo coloring-matter component in presence of one of; the herein-described organic compounds, substantially as described.

2'. The. rocess for the manufacture of monoazo yestufis, which consists in combining an orthodiazonaphtholsulfonic acid' n'aphthol, which yields violet solutions in Water, greenish-blue solutions in concentrated sulfuric acid and dyes uninordanted W001 in brownish-violet shades, becoming blue-black on treatment with chromium compounds.

In Witness whereof I have. hereunto signed my name, this 16th day of January, 1906, in the presence of two subscribing witnesses.

THILO KROEBER.

W'itnesses GEO. GIFFORD, AMAND RITTEB. 

